Field
The present disclosure is related to infusion pumps and, in particular, to the tubing used in the intravenous (IV) sets that are used with infusion pumps.
Description of the Related Art
Patients in hospitals are often provided with medical fluids that are administered through an IV infusion. Many infusion pumps operate using a peristaltic mechanism having a series of compressor blocks, or fingers, that sequentially compress and release segments of a flexible tube that is part of the IV set, commonly referred to as the “pumping segment” of the IV set, connecting the source of medical fluid, such as an IV bag, to the patient. This type of mechanism relies on the resilience of the tube to expand the tube when the compressive force is removed, thereby increasing the cross-sectional area of the tube under that finger.
Selection of a tube material having the flexibility to withstand repeated compressions while also having the necessary resilience to rebound between compressions as well as low gas permeability, to minimize the amount of air introduced into the fluid within the tube, is a challenge. A typical round tube must be compressed beyond the point at which the interior wall touches in order to completely close off the tube. This “overcompression” of the tube requires a significant application of force by the pump as well as creating additional stress in the tube walls as they are stretched during the overcompression. One commonly selected tube material is silicone, although silicone is relatively expensive and has a relatively high gas permeability.